Restricción parcial de flujo sanguíneo con resistencia, fundamento fisiológico y metodología de entrenamiento

El entrenamiento con restricción del flujo sanguíneo ha resultado ser una alternativa que logra resultados similares a los conseguidos por el entrenamiento de alta intensidad. El presente artículo ofrece el resultado de una investigación, en la que se realizó una revisión bibliográfica para indagar sobre la efectividad en el aumento de fuerza muscular, así como analizar los mecanismos de acción y metodología de aplicación práctica, mediante el método de restricción parcial de flujo sanguíneo con resistencia a bajas cargas. La literatura revisada respalda los efectos positivos de este método para generar hipertrofia y aumento de fuerza muscular, tanto en población sana como en periodo de rehabilitación. Los principales mecanismos propuestos como mediadores de esta adaptación son la elevación en la secreción de hormona del crecimiento, la señalización intracelular vía anabólica y catabólica y la contribución de procesos inflamatorios o edematosos. Se recomendó trabajar con cargas entre el 20 al 40 % de una repetición máxima y con un volumen de 75 repeticiones por sesión con entrenamiento entre 2 a 4 veces por semana, durante un tiempo mínimo de tres semanas. Se discutió sobre los efectos en la adaptación neurológica, sin existir evidencia que lo respalde. Se concluyó que el método de restricción parcial del flujo sanguíneo genera aumento de fuerza e hipertrofia y se recomienda como método complementario y alternativo al ejercicio de alta intensidad, en poblaciones que necesariamente se ven imposibilitadas de entrenar a altas intensidades.

SÍNTESE O treinamento com restrição do fluxo sanguíneo provou ser uma alternativa que alcança resultados similares aos alcançados pelo treinamento de alta intensidade. Este artigo oferece o resultado de uma pesquisa, na qual foi realizada uma revisão de literatura para investigar a eficácia no aumento da força muscular, bem como para analisar os mecanismos de ação e metodologia de aplicação prática, utilizando o método de restrição parcial do fluxo sanguíneo com resistência a cargas baixas. A literatura revisada apóia os efeitos positivos deste método para gerar hipertrofia e aumentar a força muscular, tanto na população saudável quanto no período de reabilitação. Os principais mecanismos propostos como mediadores desta adaptação são a elevada secreção hormonal de crescimento, a sinalização intracelular através de vias anabólicas e catabólicas e a contribuição de processos inflamatórios ou edematosos. Foi recomendado trabalhar com cargas entre 20 a 40% de uma repetição máxima e com um volume de 75 repetições por sessão com treinamento entre 2 a 4 vezes por semana, por um tempo mínimo de três semanas. Os efeitos sobre a adaptação neurológica foram discutidos, mas não há evidências que sustentem isto. Concluiu-se que o método de restrição parcial do fluxo sanguíneo gera maior força e hipertrofia e é recomendado como um método complementar e alternativo ao exercício de alta intensidade, em populações que são necessariamente incapazes de treinar em altas intensidades.

Blood flow restriction training has turned out to be an alternative that achieves results similar to those achieved by high intensity training. The present article offers the result of a research where, a bibliographical review was carried out to inquire about the effectiveness in increasing muscle strength, as well as to analyze the mechanisms of action and methodology of practical application, through the method of partial restriction of blood flow with endurance to low loads. The reviewed literature supports the positive effects of this method to generate hypertrophy and increase muscle strength, both in the healthy population and in the rehabilitation period. The main mechanisms proposed as mediators of this adaptation are increased secretion of growth hormone, intracellular signaling via anabolic and catabolic pathways, and the contribution of inflammatory or edematous processes. It was recommended to work with loads between 20 and 40 % of a maximum repetition and with a volume of 75 repetitions per session with training between 2 and 4 times a week, for a minimum of three weeks. The effects on neurological adaptation were discussed, without supporting evidence. It was concluded that the method of partial restriction of blood flow generates an increase in strength and hypertrophy and is recommended as a complementary and alternative method to high intensity exercise, in populations that are necessarily unable to train at high intensities.

Regulation of muscle mass by microRNAs / 体力科学

Skeletal muscle is a vital tissue not only for maintaining posture and body movements but also for energy metabolism in human body. Skeletal muscle is highly plastic in response to various stimuli, resistance exercise or anabolic hormones can increase muscle mass, which is termed “muscle hypertrophy”. Contrary, immobility, aging and severe illness can reduce muscle mass, which is termed “muscle atrophy”. Loss of skeletal muscle mass is associated with loss of independent living, the morbidity of a variety of diseases and mortality throughout life. Therefore, understanding mechanisms that regulate skeletal muscle mass is essential for improving the quality of life. Recent studies reported microRNAs (miRNAs), which is a class of non-coding RNAs, play a crucial role in the regulation of muscle mass. This review provides a current understanding of the function of miRNAs in regulation of skeletal muscle mass.

Is the myonuclear domain ceiling hypothesis dead?

Muscle fibres are multinuclear cells, and the cytoplasmic territory where a single myonucleus controls transcriptional activity is called the myonuclear domain (MND). MND size shows flexibility during muscle hypertrophy. The MND ceiling hypothesis states that hypertrophy results in the expansion of MND size to an upper limit or MND ceiling, beyond which additional myonuclei via activation of satellite cells are required to support further growth. However, the debate about the MND ceiling hypothesis is far from settled, and various studies show conflicting results about the existence or otherwise of MND ceiling in hypertrophy. The aim of this review is to summarise the literature about the MND ceiling in various settings of hypertrophy and discuss the possible factors contributing to a discrepancy in the literature. We conclude by describing the physiological and clinical significance of the MND ceiling limit in the muscle adaptation process in various physiological and pathological conditions.

Amiloidosis muscular. A propósito de un caso clínico / Muscle amyloidosis. About a clinical case / Amiloidose muscular. Sobre um caso clínico

Resumen: La amiloidosis engloba distintas enfermedades caracterizadas por el depósito extracelular de una proteína anómala e insoluble (amiloide) en los diferentes tejidos, causando su disfunción progresiva. La presentación clínica suele ser heterogénea, lo que determina el diagnóstico tardío. Para alcanzarlo se requiere de biopsia del tejido afectado, la demostración del depósito amiloide y la tipificación de la proteína que lo constituye. La detección precoz permite optimizar el tratamiento, condicionando esto el pronóstico. La miopatía amiloide asociada a una discrasia de células plasmáticas es una causa infrecuente de hipertrofia muscular; por lo que en el siguiente artículo se busca presentar un caso clínico de la misma con posterior revisión de la literatura.

Abstract: Amyloidosis encompasses various diseases characterized by the extracellular deposition of an abnormal and insoluble (amyloid) protein among the different tissues, causing its progressive dysfunction. The clinical presentation is usually heterogeneous, which determines the delays in diagnosis. To achieve this, a biopsy of the affected tissue, the demonstration of amyloid deposit and the typing of the protein that constitutes it are required. Early detection allows optimizing the treatment, conditioning the prognosis. Amyloid myopathy associated with plasma cell dyscrasia is an infrequent cause of muscle hypertrophy, for which reason the following article seeks to present a clinical case of it with a subsequent review of the literature.

Resumo: A amiloidose engloba diferentes doenças caracterizadas pela deposição extracelular de uma proteína anormal e insolúvel (amiloide) em diferentes tecidos, causando sua disfunção progressiva. A apresentação clínica costuma ser heterogênea, o que determina o diagnóstico tardio. Para tanto, é necessária a biópsia do tecido afetado, a demonstração do depósito amilóide e a tipagem da proteína que o constitui. A detecção precoce permite otimizar o tratamento, condicionando o prognóstico. A miopatia amilóide associada à discrasia das células plasmáticas é uma causa rara de hipertrofia muscular; Portanto, o seguinte artigo busca apresentar um caso clínico desta com posterior revisão da literatura.

Mechanism of ribosome biogenesis and exercise adaptation of skeletal muscle hypertrophy / 中国组织工程研究

BACKGROUND: Research evidence shows that skeletal muscle contractile activity can induce ribosomal biogenesis, which plays an important role in the control of skeletal muscle mass. OBJECTIVE: To review the main mechanism of ribosome biogenesis in skeletal muscle hypertrophy, upstream regulatory signals of ribosomal biogenesis in skeletal muscle, and effect of exercise on ribosomal biogenesis, and to explore the ribosome biogenesis mechanism of exercise-induced skeletal muscle hypertrophy. METHODS: Relevant studies about exercise, skeletal muscle hypertrophy and ribosome biogenesis in CNKI, Wanfang, and PubMed databases were searched. The key words were “exercise, resistance training, skeletal muscle hypertrophy, protein synthesis, ribosome biogenesis” in English and Chinese. Relevant literatures published from 1999 to 2019 were searched and screened according to inclusion and exclusion criteria. RESULTS AND CONCLUSION: (1) Ribosome biogenesis as a main source of translational capacity plays an important role in muscle growth. (2) A single bout of resistance exercise can promote the ribosome biogenesis. However, cumulative bouts of resistance exercise eventually lead to the accumulation of mature rRNAs, leading to increased concentration of total RNA, which promote the growth of skeletal muscle. (3) Ribosome biogenesis may be the key molecular mechanism for the regulation of skeletal muscle hypertrophy induced by resistance training. (4) Moderate-volume resistance training led to adaptations to resistance training. This hypertrophy was associated with volume-dependent regulation of total RNA. This suggests that ribosomal biogenesis regulates the dose-effect relationship between training volume and muscle hypertrophy.

Does whole-body electrical muscle stimulation combined with strength training promote morphofunctional alterations?

OBJECTIVES: The aim of this study was to evaluate the effects of 8 weeks of strength training (ST) combined with whole-body electrical stimulation (EMS) on morphofunctional adaptations in active individuals. METHODS: Fifty-eight volunteers were randomly distributed into the following groups: an untrained control (UN) group (n=16), an ST group (n=21) or an ST combined with EMS (ST+EMS) group (n=21). Both intervention groups (the ST and ST+EMS groups) performed 3 exercises (biceps curl, back squats and high-pulley tricep extensions) twice a week for 8 weeks. The subjects performed 3 sets of 8 to 12 maximum repetitions (MRs) with a 90-second rest duration between sets. The ST+EMS group performed the resistance training exercises wearing a whole-body suit that provided electrical stimulation at frequencies between 80-85 Hz, with a continuously bipolar impulse duration and pulse breadth of 350 µs. The intensity for each muscle group was controlled by Borg's category ratio (CR)-10 scale; the intensity started at 5-6 and eventually reached 7-8. One-repetition maximum strength (1RM) and muscle thickness (MT) were measured before and after the training intervention. MT was evaluated in the biceps brachii (BB), triceps brachii (TB), and vastus lateralis (VL). RESULTS: No differences (p>0.05) were found between the ST and ST+EMS groups. Improvements (p<0.05) in the absolute values of the morphofunctional parameters after the training protocol were observed. Significant differences were found between both the intervention groups and the UN group (p<0.05). The ST+EMS group presented high percentage changes (p<0.05) in muscular strength for the 1RMsquat (43.2%, ES=1.64) and the MT of the BB (21.6%, ES=1.21) compared to the ST (20.5%, ES=1.43, 11.9%, ES=0.77) group. CONCLUSIONS: Our data suggest that the combination of ST+EMS may promote alterations in muscle strength and MT in healthy active subjects.

The Effect of Physical Resistance Training on Baroreflex Sensitivity of Hypertensive Rats / Efeito do Treinamento Físico Resistido na Sensibilidade Barorreflexa de Ratos Hipertensos

Abstract Background: Baroreceptors act as regulators of blood pressure (BP); however, its sensitivity is impaired in hypertensive patients. Among the recommendations for BP reduction, exercise training has become an important adjuvant therapy in this population. However, there are many doubts about the effects of resistance exercise training in this population. Objective: To evaluate the effect of resistance exercise training on BP and baroreceptor sensitivity in spontaneously hypertensive rats (SHR). Method: Rats SHR (n = 16) and Wistar (n = 16) at 8 weeks of age, at the beginning of the experiment, were randomly divided into 4 groups: sedentary control (CS, n = 8); trained control (CT, n = 8); sedentary SHR (HS, n = 8) and trained SHR (HT, n = 8). Resistance exercise training was performed in a stairmaster-type equipment (1.1 × 0.18 m, 2 cm between the steps, 80° incline) with weights attached to their tails, (5 days/week, 8 weeks). Baroreceptor reflex control of heart rate (HR) was tested by loading/unloading of baroreceptors with phenylephrine and sodium nitroprusside. Results: Resistance exercise training increased the soleus muscle mass in SHR when compared to HS (HS 0.027 ± 0.002 g/mm and HT 0.056 ± 0.003 g/mm). Resistance exercise training did not alter BP. On the other hand, in relation to baroreflex sensitivity, bradycardic response was improved in the TH group when compared to HS (HS -1.3 ± 0.1 bpm/mmHg and HT -2.6 ± 0.2 bpm/mmHg) although tachycardia response was not altered by resistance exercise (CS -3.3 ± 0.2 bpm/mmHg, CT -3.3 ± 0.1 bpm/mmHg, HS -1.47 ± 0.06 bpm/mmHg and HT -1.6 ± 0.1 bpm/mmHg). Conclusion: Resistance exercise training was able to promote improvements on baroreflex sensitivity of SHR rats, through the improvement of bradycardic response, despite not having reduced BP.

Resumo Fundamento: Os barorreceptores atuam como reguladores da pressão arterial (PA); no entanto, sua sensibilidade encontra-se prejudicada em pacientes hipertensos. Dentre as recomendações para a redução da PA, o treinamento físico tem se tornado um importante adjunto na terapia dessa população. Porém, ainda há diversos questionamentos sobre os efeitos de treinamento físico resistido nessa população. Objetivo: Avaliar o efeito do treinamento físico resistido na PA e na sensibilidade de barorreceptores em ratos espontaneamente hipertensos (SHR). Método: Ratos SHR (n = 16) e Wistar (n = 16) com 08 semanas de idade foram aleatoriamente divididos em 4 grupos: controle sedentário (CS, n = 8); controle treinado (CT, n = 8); SHR sedentário (HS, n = 8) e SHR treinado (HT, n = 8). O treinamento físico foi realizado em aparato com degraus (1,1 × 0,18 m, 2 cm entre os degraus, 80° inclinação) com peso fixado na cauda, (5 vezes por semana durante 8 semanas). O controle barorreflexo da frequência cardíaca (FC) foi testado com estímulos de fenilefrina e nitroprussiato de sódio. Resultados: O treinamento resistido foi capaz de aumentar a massa muscular do sóleo em ratos SHR (HS 0,027 ± 0,002 g/mm e HT 0,056 ± 0,003 g/mm). Não houve alteração da PA com o treinamento. Por outro lado, houve melhora na resposta bradicárdica da sensibilidade barorreflexa no grupo HT (HS -1,3 ± 0,1 bpm/mmHg e HT -2,6 ± 0,2 bpm/mmHg), no entanto, a resposta taquicárdica não foi alterada pelo exercício resistido (CS -3,3 ± 0,2 bpm/mmHg, CT -3,3 ± 0,1 bpm/mmHg, HS -1,47 ± 0,06 e HT -1,6 ± 0,1). Conclusão: O exercício físico resistido foi capaz de otimizar a sensibilidade barorreflexa dos ratos SHR por meio da melhora à resposta bradicárdica, apesar de não alterar a PA.

Bilateral Hypertrophy of Abductor Digiti Minimi Simulating a Localized Soft Tissue Mass: A Case Report / 대한족부족관절학회지

Soft tissue tumors of the foot have a low incidence rate, and most of them are symptom free, thus it is difficult to diagnose accurately. Herein, we report a 15-year-old male patient who had swelling without pain on the lateral margin of both feet. We performed excisional biopsy of the abductor digiti minimi via subtotal resection, following radiograph and magnetic resonance imaging. According to the histological analysis, hypertrophy of abductor digiti minimi was positive, and other soft tissue tumors were negative. Six months after the operation, normal appearance of both feet was maintained and the patient was satisfied with the result.

Ultrasound imaging in women's arm flexor muscles: intra-rater reliability of muscle thickness and echo intensity

ABSTRACT Background Different ultrasound parameters have been frequently used to assess changes associated with training, aging, immobilization, and neuromuscular diseases. However, an exploratory reliability analysis of the echo intensity (EI) and muscle thickness (MT) of the forearm flexors is scarce, especially in women. Objective The purpose of the present study was to determine the intra-rater reliability of MT and EI assessed by ultrasound in young women. Method Ultrasonographic MT and EI were acquired in the forearm flexors of 41 young women (22±2 yrs). Reliability was calculated using intraclass correlation coefficient (ICC2,1), standard error of measurement (SEM), coefficient of variation (CV), smallest detectable change (SDC), and Bland and Altman plot analysis. Results ICC values for MT and EI were 0.88 (95% CI: 0.78-0.93). The SEM and CV values were lower than 10%. Bland and Altman analysis revealed that ultrasound mean differences were 0.27 mm (Limits of Agreement - LOA 95%: - 2.6 to 3.2 mm) and -0.09 a.u. (LOA 95%: - 10.9 to 10.7 a.u.). Conclusion MT and EI assessed by ultrasonography in young women appear to be reliable and may be used to monitor changes in muscle mass induced by strength training when these changes exceed the precision of ultrasound.

Clinical Feature Analysis of Papillary Muscle Hypertrophic Cardomyopathy in 21 Patients / 中国循环杂志

Objective: To explore the clinical and magnetic resonance imaging (MRI) features of papillary musclehypertrophic cardiomyopathy. Methods: Our research contained 2 groups: Papillary muscle hypertrophic cardiomyopathy group,n=21 patients treated in our hospital from 2013-01 to 2015-12 including 18 male and 3 female; Control group,n=50 subjects without cardiovascular disease those were conifrmed by our hospital at the same period of time. Clinical and MRI examinations were conducted in all patients, the ifndings were compared between 2 groups. Results: Compared with control subjects, papillary musclehypertrophic cardiomyopathy patients had the main symptoms of shortness of breath, chest tightness and pain; associated with systolic murmur; ECG could be normal or with T wave inversion; cardiac MRI showed that 1/2 papillary muscle diameter>1.1cm. Blood levels of triglyceride, left atrial diameter, inter-ventricular septum thickness, the values of E/A and EDT were statistically different between 2 groups, allP<0.05. Conclusion: Clinical features of papillary muscle hypertrophic cardiomyopathy were lack of speciifcity, the morbidity and clinical signiifcance should be further investigated.

Effect of vitamin D on overload-induced hypertrophy of skeletal muscle and expression of vitamin D receptor in aged rats / 第二军医大学学报

Objective To establish an overload-induced hypertrophy model in aged rats by severing the distal tendon of gastrocnemius muscle, and to investigate the effect of vitamin D on overload-induced hypertrophy and the related mechanism. Methods A total of 20 male rats (24 months old) underwent tenotomy of the achilles tendon of the gastrocnemius muscle in the left hind limb; and a control sham operation was performed on the right hind limb. The rats were randomly divided into control group and experimental group. Experimental group received 1 000 IU/kg of vitamin D by intragastric administration, and the control group was given soybean oil. The animals were sacrificed one week later, the blood samples were collected, and the left, right hind musculus plantaris tissues were weighed and kept in liquid nitrogen. ELISA assay was used to examine serum 25(OH)D level and vitamin D receptor (VDR) in the skeletal muscle. Western blotting analysis was used to examine mTOR, rpS6 protein and their phosphorylation. Results The food intake and body mass were not significantly different between the two groups. Compared with the control side, vitamin D supplement significantly increased the muscle mass of the overload side in both groups (P<0. 05); and the mass of the overload side in the vitamin D supplement group was significantly higher than that in the control group (P<0. 05), while the mases were not significantly different for the sham sides in the two groups. The results of ELISA assay showed that vitamin D supplement significantly increased serum 25(OH)D levels in rats compared with the control group (P< 0. 05), and significantly promoted the expression of VDR in the overload side compared with the Sham side (P<0. 05), while there was no significant difference between the two sides in the control group. Western blotting analysis showed that p-rpS6/rpS6 and p-mTOR/mTOR ratios in the overload sides were higher than those in the Sham sides, but significant difference was only found for the vitamin D supplement group (P<0. 05). Conclusion Tenotomy of the achilles tendon of the gastrocnemius muscle can effectively promote the skeletal muscle hypertrophy in aging rats, and vitamin D supplement can further enhance overload-induced skeletal muscle hypertrophy, which might be related to VDR expression in skeletal muscle and protein synthesis protein mTOR and rpS6.

Construction of a eukaryotic expression vector for pEGFP-FST and its biological activity in duck myoblasts

Background Follistatin (FST), a secreted glycoprotein, is intrinsically linked to muscle hypertrophy. To explore the function of duck FST in myoblast proliferation and differentiation, the pEGFP-FST eukaryotic expression vector was constructed and identified. The biological activities of this vector were analyzed by transfecting pEGFP-FST into cultured duck myoblasts using Lipofectamine™ 2000 and subsequently determining the mRNA expression profiles of FST and myostatin (MSTN). Results The duck pEGFP-FST vector was successfully constructed and was confirmed to have high liposome-mediated transfection efficiency in duck myoblasts. Additionally, myoblasts transfected with pEGFP-FST had a higher biological activity. Significantly, the overexpression of FST in these cells significantly inhibited the mRNA expression of MSTN (a target gene that is negatively regulated by FST). Conclusions The duck pEGFP-FST vector has been constructed successfully and exhibits biological activity by promoting myoblast proliferation and differentiation in vitro.

Comparação entre diferentes modelos de periodização sobre a força e espessura muscular em uma sequência dos menores para os maiores grupamentos musculares / Comparison between different periodization models on muscular strength and thickness in a muscle group increasing sequence

INTRODUÇÃO: Estudos comparando modelos de periodização em sequências de treinamento resistido (TR) realizadas do menor para o maior grupo muscular sobre as alterações musculares em indivíduos destreinados em TR são escassos. OBJETIVO: Comparar o efeito da periodização ondulatória (PO) e da periodização linear (PL) sobre a força máxima e hipertrofia muscular em uma sequência de execução dos exercícios dos menores para os maiores grupamentos musculares. MÉTODOS: Vinte e nove homens não experientes em (TR) foram distribuídos aleatoriamente em três grupos: PO (n =10), PL (n = 13) e grupo controle (GC, n = 9). Os indivíduos realizaram o teste de uma repetição máxima (1RM) nos exercícios rosca bíceps (RB), rosca tríceps (RT), puxada aberta (PA) e supino reto (SR), contração isométrica voluntária máxima (CIVM) e espessura muscular (EM) para flexores de cotovelo (FC) e extensores de cotovelo (EC) antes e após o período de 12 semanas de treinamento. O grupo PO variou o volume e a intensidade do treinamento diariamente, e o grupo PL a cada quatro semanas. O GC não realizou TR. Foi realizada uma ANOVA de dois caminhos com medidas repetidas, e cálculo do tamanho do efeito (TE), nas cargas obtidas para analisar o efeito do tratamento sobre as variações pré- e pós-período de TR. RESULTADOS: Os principais achados do estudo foram: 1) o grupo PO apresentou maior TE para 1RM dos exercícios RT e RB e para EM dos FC e EC quando comparado ao grupo PL; 2) não houve diferença no TE para os exercícios SR e PA que finalizavam a sessão. CONCLUSÃO: Ambos os modelos de periodização adotados foram eficientes para promover aumentos de força e hipertrofia muscular. Contudo, segundo o cálculo do TE, a PO promoveu maior incremento da força máxima nos exercícios que iniciaram a sessão e hipertrofia muscular.

INTRODUCTION: Studies comparing periodization models in sequences that begin with small muscle group and progressed toward large muscle group in untrained subjects in resistance training are scarce. OBJECTIVE: The purpose of this study was to compare the effects of ondulatory periodization and linear periodization models on maximum strength and muscular hypertrophy in a muscle group increasing exercise sequence. METHODS: Twenty-nine men with no experience in RT were randomly assigned into three groups: ondulatory periodization (OP, n = 10), linear periodization (LP, n = 13), and control group (CG, n = 9). The individuals performed 1RM tests in four exercises: biceps curl (BC), triceps extension (TE), lat pull down (LPD) and bench press (BP) and evaluations of maximum voluntary isometric contraction (MVIC), muscle thickness of elbow flexors (EF) and elbow extensors (EE) before and after the 12 weeks of training were carried out. The OP group varied in volume and intensity on a daily basis, while LP group varied every four weeks. The CG did not perform ST. A two-way ANOVA with repeated measures and the effect size (ES) were used to analyze muscle thickness, 1RM load improvement in each of the four exercises and the MVIC between groups. RESULTS: The major findings of this study were: 1) OP showed major ES for 1RM of BC and TE and for muscle thickness of EF and EE when compared with LP. 3) The ES data did not show significant differences for BP and LPD which finished the training session. CONCLUSIONS: We conclude that both periodization models were efficient at improving strength gains and muscular growth. However, ES data show that OP promotes major gains in strength for exercises that are positioned at the beginning of the session and hypertrophy.

Consumo de oxigênio de recuperação em resposta a duas sessões de treinamento de força com diferentes intensidades / Recovery oxygen uptake in response to two resistance training sessions at different intensities

O objetivo do presente estudo foi comparar o comportamento do consumo de oxigênio (VO2) em resposta a uma sessão de treinamento de força (TF) com objetivo em hipertrofia muscular (HP) com uma sessão com objetivo em resistência muscular localizada (RML). Nove indivíduos do sexo masculino (23,1 ± 2,1 anos) foram recrutados para este estudo. A força muscular dinâmica foi mensurada através do teste de 1RM. O VO2 foi coletado durante o repouso e 10 minutos de recuperação com um analisador de gases (CPX/D). As sessões foram compostas por um exercício de membros superiores (supino) e um de membros inferiores (agachamento), e compreenderam a execução de três séries de 6-8 repetições máximas (RM) a 80 por cento de 1RM para HP e 15-20 RM a 55 por cento de 1RM para RML. Foram analisados os dados de VO2 pós-exercício (EPOC), gasto energético (GE) de recuperação e constante de tempo de VO2 (CT). Foi observado que ambas sessões provocaram comportamento significativamente elevado de VO2 durante os 10min de recuperação em relação aos valores de repouso. Não houve diferenças significativas entre os valores de EPOC (litros) para HP (2,21 ± 0,54) e RML (2,60 ± 0,44), GE (kcal) para HP (10,36 ± 2,53) e RML (12,18 ± 2,04) e CT (segundos) para HP (56 ± 7) e RML (57 ± 6) (p > 0,05). Esses resultados demonstraram que uma sessão de TF com objetivo em RML é capaz de causar distúrbios metabólicos semelhantes àqueles provocados por uma sessão de HP, mesmo que seja em menor intensidade relativa a carga máxima.

The purpose of the present study was to compare the oxygen uptake ( VO2) behavior in response to a resistance exercise (RE) session with aim of hypertrophy (HP) with another session with aim of local muscular endurance (LME). Nine young men (23.1± 2.1 years) voluntarily participated in the present study. Dynamic muscle strength was measured with one repetition maximum test (1RM). O VO2 was collected at rest and ten minutes after exercise with a gas analyzer (CPX/D). The RE protocols were composed of one upper body exercise (bench press) and one lower body exercise (squat) with the execution of 3 sets of 6-8 maximum repetitions (RM) with 80 percent of 1RM in HP session and 3 sets of 15-20 RM with 55 percent of 1 RM in LME session. Exercise post oxygen consumption (EPOC), energy cost (EC) and time constant (TC) of VO2 were analyzed. The results showed that both RE sessions provoked significant elevated VO2 after RE in comparison to rest values. There were no differences between groups in the EPOC (l) (HP: 2.21 ± 0.54 vs. LME: 2.60 ± 0.44), EC (Kcal) (HP: 10.36 ± 2.53 vs LME: 12.18 ± 2.04) and TC of VO2 (s) (HP: 56 ± 7 vs. LME: 57 ± 6) (p>0.05). These results demonstrated that a RE session with the aim of LME gain is capable of causing similar metabolic impact to the RE session with HP aim, even if it is performed at lower intensity concerning maximal load.

Electroacupuncture accelerates recovery of muscle atrophy induced by hindlimb suspension in mouse skeletal muscle / 全日本鍼灸学会雑誌

[Objective]The influence of electroacupuncture (EA) stimulation on physical inactivity is not clear. This study aimed to investigate the effects of EA on the recovery of mouse soleus muscle atrophy induced by hindlimb suspension (HS).<BR>[Methods]We used 8-week-old male ICR mice (n = 20). The mice were divided into 4 groups:the No treatment group (NT, n = 5), HS group (HS, n = 5), Control group (CT, n = 5), and Reloading-with-EA-stimulation group (EA, n = 5). HS mice were suspended for up to 14 days. CT and EA mice were reloaded for an additional 14 days after the HS for 14 days. The HS method used a modified version of an apparatus used in a previous study. EA mice received EA every other day immediately after reloading and were stimulated in the triceps surae muscle at 10 Hz for 30 min with a stainless steel needle. The weight, muscle fiber area size and number of macrophages in the soleus muscle were analyzed.<BR>[Results]The number of skeletal muscle macrophages was increased significantly in EA mice compared with that in CT mice (P < 0.01). The soleus muscle weight and muscle fiber cross-sectional area were decreased in HS mice compared with NT mice (P < 0.01). However, the muscle weight of EA and CT mice increased significantly compared with that of HS mice (P < 0.01). In addition, the muscle weight of EA mice was significantly higher than that of CT mice (P < 0.01), without a significant difference in muscle fiber cross-sectional area between CT and EA mice. <BR>[Conclusion]These results indicate that EA was effective in facilitating the recovery of skeletal muscle atrophy in mice. In addition, resolution of the skeletal muscle atrophy suggested the satellite cell activation by macrophages, because macrophages invaded the skeletal muscle after EA stimulation.

Changes in Muscular Lipids in Unilateral Isolated Hypertrophy of Gastrocnemius Muscle Can Be Revealed by 1H MR Spectroscopy

OBJECTIVE: To test whether proton magnetic resonance spectroscopy (1H-MRS) reveals changes in the lipid content of the gastrocnemius muscle (GM) and soleus muscle (SOL) of a patient with unilateral isolated hypertrophy of the right GM. MATERIALS AND METHODS: 1H-MRS was performed on a 1.5 Tesla (T) whole-body unit. Muscular lipids inside SOL and GM were assessed in both calves of the patient by a STEAM (stimulated echo acquisition mode) localization sequence. Results were compared to a control group of four healthy volunteers. RESULTS: Total amount of muscular lipids in the hypertrophic GM of the patient was clearly increased compared to the controls (38.7 versus 21.8+/-3.5 a.u.) while intramyocellular lipids of the adjacent SOL were lower compared to the contralateral healthy leg. CONCLUSION: Muscular lipids are substrates for metabolism and can be assessed non-invasively by 1H-MRS. 1H-MRS is considered to be a helpful tool in clinical assessment of muscle metabolism in cases with muscular hypo- or hypertrophy.

A Comparative Study of the Prolonged Effect with Neurectomy & Botox Injection Method on the Gastrocnemius Muscle Hypertrophy

PURPOSE: There was no controlled study on botox injection and neurectomy for treatments of muscle hypertrophy. Although many studies have shown the clinical effects of each treatment, it was not able to evaluate and compare the effects of each treatment because there was no comparison of the two treatments under the same experimental condition. Hence, the aim of this study is to com METHODS: The study was carried out on 21 rabbits. 9 rabbits received botox injection(botox injection group), and neurectomy was performed to another 9 rabbits (neurectomy group). 3 rabbits did not receive any treatment(control group). To compare and analyze the effects of muscular atrophy, muscle was stained with NADH-TR, and the changes in size of the muscle fiber were examined. And the electromyography was examined. In each group, muscle fiber was stained and electromyography was performed 2, 3, and 6 months after injection or operation. RESULTS: In histological test and electromyography, in the neurectomy group, the size of muscular fiber and amplitude of electromyography decreased until 2 months after neurectomy. And decreased results were maintained with the passage of time. It showed irreversible aspect. On the other hand, in the botox injection group, the decrease in the size of muscular fiber and amplitude of electromyography was observed until 2 months after injection. In 3 months after the injection, it was slowly getting back to original size and had almost recovered by 6 months after the injection. It showed reversible aspect. CONCLUSION: This study shows researches about clinical effect of botox injection and neurectomy coincide with the results of experiment under the same experimental condition.

Pseudohypertrophy of the Calf Muscles in a Patient with Diabetic Neuropathy: A Case Report

Partial or complete loss of innervation of skeletal muscle leads to muscle weakness and atrophic changes, resulting in decreased muscle volume with fatty replacement. Rarely, enlargement of the affected muscle may occur, related to two processes: true hypertrophy and pseudohypertrophy. We report CT and MR findings of the pseudohypertrophy of calf muscles, especially the soleus and gastrocnemius muscles, in a patient with diabetic neuropathy that showed increased muscle volume with diffuse fatty replacement and the presence of scanty muscle fibers.

Effects of Neuromuscular Electrical Stimulation on the Muscle Hypertrophy and Cross Training Effect

OBJECTIVE: To evaluate the effect of electrical stimulation on muscle strength, muscle bulk and envelope amplitude. METHOD: Twenty right handed healthy men and women (8 : 12) volunteered to be subjects whose mean age were 25.5+/-2.8 years. Left thenar muscle was stimulated at 40 Hz frequency for 20 minutes, every weekday for 2 weeks. Maximal tip pinch power of first and second finger, and cross sectional area of abductor pollicis brevis were assessed before and after electrical stimulation in both hands. RESULTS: Maximal tip pinch power increased in bilateral hands. The thickness and cross sectional area of both thenar muscles were increased, but they were significant only in left side. Envelope amplitude increased significantly in left thenar muscle at maximal voluntary contraction, and showed a tendency to increase in right side at each percent of 10, 30, 50, 100 and in left side at 10, 30, 50% maximal voluntary contractions. CONCLUSION: The electrical stimulation on unilateral muscle induced the increment of bilateral muscular strength. The neural factor and muscle hypertrophy are responsible for the increased strength of the stimulated muscle and the increase in the nonstimulated muscle strength is related to the cross-training effect and adaptation effect.

The Clinical Features and the Change of Extraocular Muscle at the First Visit in Hyperthyroidism Patients

PURPOSE: To investigate of the orbital manifestations and the changes in extraocular muscles of hyperthyroidism patients at the first visit to out-patient clinic. METHODS: We reviewed the orbital manifestation and extraocular muscle hypertrophy of the patient with the hyperthyroidism who are transfered from internal medicine to ophthalmology. We used the NOSPECS system to classify the patients and checked the orbital CT, schirmer test, visual field exam, and the Hertel's exophthalmometer for evaluation of ocular symptoms. RESULTS: Mean age of the group was 34.62 +/- 9.89 years. They were 5 males and 11 females. According to NOSPECS system, the change of eyelid and ptoptosis was 1.56 and 1.31, the change of extraocular muscle and the degree of corneal involvement was 0.56, sight loss due to optic nerve involvement was 0.25 in ophthalmic index. The thickness of the extraocular muscles measured by CT scan showed 4.40mm in the superior muscle group, 3.90mm in the inferior rectus muscle, 3.42mm in the medial rectus muscle, 3.40mm in the lateral rectus muscle. CONCLUSION: According to NOSPECS system, the ophthalmic index was 4.18. Especially, the changes of eyelid were remarkable(1.56) among the signs. The hypertrophy of superior muscle group(superior rectus and levator palpebral muscle) and inferior rectus muscle were eminent, measured by CT scan.